Leave Your Message
Explore our precision-engineered bare copper ground wire solutions, purpose-built for flexible PCB assemblies, FPC grounding, and high-density circuit board applications across industrial and consumer electronics sectors.
Bare copper ground wire is an uncoated, high-purity copper conductor that plays a critical role in the grounding and shielding architecture of flexible circuit board (FPC) systems. As electronics continue to shrink while demanding higher performance, the quality and flexibility of ground wiring has become a decisive factor in product reliability.
Manufactured from 99.9%+ electrolytic-grade copper, bare copper ground wire delivers exceptional electrical conductivity (≥58 MS/m), outstanding thermal performance, and superior corrosion resistance in standard operating environments. The absence of insulation allows direct contact with PCB ground planes, enabling low-impedance grounding paths essential for signal integrity in high-frequency flexible circuit assemblies.
Flexible circuit boards (FPCs) are designed to bend, fold, and conform to complex geometries inside compact devices. The ground wire used in these assemblies must match this flexibility without work-hardening or fracturing under repeated mechanical stress. Soft-annealed bare copper wire, with elongation rates exceeding 25%, ensures consistent electrical contact even in dynamic bending applications such as foldable smartphones, wearables, and robotic joints.
Bare copper ground wire for FPC applications is available in multiple structural forms: solid single-strand wire for rigid sections, fine multi-strand twisted wire for flexible zones, and braided flat configurations for high-current ground buses. Each variant is optimized for specific flex-cycle requirements, current-carrying capacity, and spatial constraints within the PCB stack-up.
In high-speed digital and RF flexible circuits, bare copper ground wires serve as the backbone of the EMI suppression system. Proper grounding with low-resistance bare copper conductors reduces ground bounce, minimizes return current loops, and prevents electromagnetic interference from propagating through the flexible substrate — a critical requirement in 5G modules, automotive radar sensors, and medical imaging flex assemblies.
Electrolytic-grade copper ensures maximum conductivity and minimal resistive losses in FPC ground paths.
Multi-strand configurations down to 0.05mm per wire enable extreme flexibility for high-cycle bending applications.
Diameter tolerances within ±0.01mm guarantee consistent fit within FPC connectors and ground pad layouts.
AWG 30 to AWG 4, custom pitch, flat or round profiles — engineered to your exact PCB design requirements.
While tinned and silver-coated copper wires offer oxidation resistance, bare copper ground wire provides a 3–5% lower contact resistance at the PCB pad interface, critical for high-frequency signal return paths. In controlled PCB assembly environments with proper surface treatment, bare copper's superior solderability and direct conductivity make it the preferred choice for precision flexible circuit board grounding — especially in aerospace, medical, and 5G communication applications where every milliohm counts.
The global flexible printed circuit board market is projected to reach USD 42 billion by 2030, growing at a CAGR of over 10%. This explosive growth is directly driving demand for high-performance bare copper ground wire solutions that meet the increasingly stringent requirements of next-generation electronics.
Foldable smartphones, AR/VR headsets, and ultra-thin laptops require FPC assemblies with ground wires as fine as 0.05mm. The push toward thinner form factors is accelerating adoption of ultra-fine bare copper stranded wire with enhanced flexibility ratings exceeding 500,000 bend cycles.
Electric vehicles use over 3km of wiring per unit, with flexible circuits in battery management systems, ADAS sensors, and in-cabin displays. Bare copper ground wire for automotive FPCs must meet AEC-Q200 reliability standards and withstand temperature ranges from -40°C to +150°C.
5G mmWave antenna modules rely on flexible circuits with precision ground planes. At frequencies above 28GHz, ground wire skin effect becomes critical — requiring ultra-pure bare copper with surface roughness below 0.5μm Ra to minimize high-frequency resistive losses.
Implantable and skin-contact medical devices demand biocompatible, ultra-flexible grounding solutions. Bare copper ground wire in medical FPCs undergoes rigorous sterilization compatibility testing and must maintain electrical performance through over 1 million flex cycles.
Collaborative robots (cobots) and industrial IoT sensors use FPC assemblies in joint actuators and sensor arrays. Bare copper ground wire must deliver reliable grounding under continuous vibration, thermal cycling, and chemical exposure in factory environments.
Growing RoHS and REACH compliance requirements are driving demand for lead-free, halogen-free bare copper ground wire. Xingma's ISO14001-certified manufacturing process ensures environmentally responsible production with full traceability of copper sourcing and processing.
From automotive electronics to cutting-edge communication infrastructure, bare copper ground wire is indispensable across diverse industrial and commercial flexible circuit board applications.
In electric vehicle and energy storage BMS modules, bare copper ground wire provides the critical low-resistance ground reference for cell voltage monitoring circuits. FPC-based BMS designs use fine-pitch bare copper ground traces to ensure accurate cell balancing measurements with millivolt-level precision across 100+ cell stacks.
Smartphone and automotive camera modules use multi-layer FPCs with integrated bare copper ground shields to prevent image sensor noise. The ground wire network in these assemblies must maintain impedance below 0.1Ω while surviving over 200,000 camera actuator cycles in autofocus mechanisms.
Display flex cables in foldable and convertible devices route bare copper ground conductors alongside high-speed data lines. These ground wires must maintain consistent impedance through 30,000+ open/close cycles while preventing EMI crosstalk between USB4 and display signal pairs.
Avionics FPC assemblies in aircraft and satellites demand bare copper ground wire with MIL-SPEC compliance, outgassing certification (NASA ASTM E595), and performance stability across extreme temperature ranges. Ground wire integrity is safety-critical in flight control and navigation flex circuits.
| Parameter | Standard Grade | High-Flex Grade | Ultra-Fine Grade |
|---|---|---|---|
| Copper Purity | ≥99.9% | ≥99.95% | ≥99.99% |
| Conductor Type | Solid / 7-strand | 19–49 strand | 133–1330 strand |
| Wire Diameter Range | AWG 4–20 | AWG 20–28 | AWG 28–40 |
| Single Strand Diameter | 0.2–0.5mm | 0.08–0.2mm | 0.03–0.08mm |
| Conductivity | ≥57 MS/m | ≥58 MS/m | ≥58.5 MS/m |
| Elongation at Break | ≥20% | ≥28% | ≥35% |
| Flex Cycle Rating | 50,000 | 500,000 | 1,000,000+ |
| Temperature Range | -20°C to +105°C | -40°C to +130°C | -55°C to +150°C |
| Typical Applications | General FPC grounding | Consumer electronics FPC | Medical / Aerospace FPC |
Zhejiang Xingma Co., Ltd. was established in 2019 and is located in Liushi, the capital of electrical appliances in China. It is an enterprise mainly engaged in metal products, wire and cable processing and sales; import and export of goods and technology. The company revolves around the construction of a modern enterprise mechanism and mass production of mechanical automation.
The leading products include copper wire, copper braided wire, copper stranded wire, soft copper stranded wire, brush wire, carbon brush wire, soft connection series products, metal stamping parts and other products — best-selling at home and abroad, deeply trusted and welcomed by customers worldwide.
The company abides by the Universal Declaration of Human Rights and major United Nations conventions, respects human and labor rights, and is committed to scientific and technological innovation. Passed ISO9001 quality system certification and ISO14001 environmental management system certification in 2020. In 2021, it won the star enterprise and excellent production enterprise awards.
Zhejiang Xingma Copper Industry Co., Ltd. operates a factory building with a construction area of more than 10,000 square meters and more than 100 employees. The facility is equipped with more than 300 domestic top-level manufacturing machines including:
Dingtian wire drawing machines, Fuchuan beam machines, pipe twisting machines, braiding machines, annealing furnaces, middle drawing machines, automatic cutting machines, welding machines, air dryers, microscope hardness testers, automatic punching machines, 160-ton punching machines, wire dividing machines, flattening machines, large polishing machines, stamping parts cleaning machines, bench drills, and packing machines.
This comprehensive manufacturing infrastructure enables Xingma to deliver bare copper ground wire for flexible circuit board components with consistent quality, tight dimensional tolerances, and rapid customization response — supporting customers from prototype to mass production scale.
Discover our full range of high-performance copper wire and connectivity solutions designed for flexible PCB grounding, EMI shielding, soft connections, and precision electrical applications.
